Hydraulic actuators or dampers are used to control motion in a variety of systems such as, for example, passive, semi-active, or active suspension systems. In some applications, a hydraulic system having a damper and/or actuator may additionally include an accumulator that is designed to receive and/or supply fluid to the damper or actuator. The accumulator may serve, for example, to accommodate variations in the fluid capacity of the damper or actuator, and/or to accommodate fluid expansion or contraction (e.g., due to thermal variations) during operation of the hydraulic system.